1. **State the problem:** Solve the equation $5x + 9 = 2(x + 3)$. 2. **Expand the right side:** Use the distributive property $a(b+c) = ab + ac$ to get $5x + 9 = 2x + 6$. 3. **Isolate variable terms on one side:** Subtract $2x$ from both sides: $$5x + 9 - \cancel{2x} = \cancel{2x} + 6 - 2x \implies 5x - 2x + 9 = 6$$ 4. **Simplify:** $$3x + 9 = 6$$ 5. **Isolate the variable term:** Subtract 9 from both sides: $$3x + 9 - \cancel{9} = 6 - \cancel{9} \implies 3x = -3$$ 6. **Solve for $x$:** Divide both sides by 3: $$\frac{3x}{\cancel{3}} = \frac{-3}{\cancel{3}} \implies x = -1$$ 7. **Final answer:** $x = -1$